<template>
  <div class="container">
    <div class="row">
      <div class="col-12 pt-3">
        <table class="table table-bordered">
          <thead>
            <tr>
              <th scope="col">编号</th>
              <th scope="col">科目</th>
              <th scope="col">成绩</th>
              <th scope="col">考试时间</th>
              <th scope="col">操作</th>
            </tr>
          </thead>
          <tbody>
            <tr v-for="(item, index) in list" :key="item.id">
              <th scope="row">{{ item.id }}</th>
              <td>{{ item.subject }}</td>
              <td :class="{ 'not-passed': item.score < 60 }">{{ item.score }}</td>
              <td>{{ item.time }}</td>
              <td>
                <button type="button" class="btn btn-link" @click="del(index)">删除</button>
              </td>
            </tr>
            <tr class="bg-light">
              <th scope="row">统计</th>
              <td colspan="2">总分：0</td>
              <td colspan="2">平均分：0</td>
            </tr>
          </tbody>
          <tfoot style="display: none">
            <tr>
              <td class="text-center" colspan="5">暂无数据</td>
            </tr>
          </tfoot>
        </table>
      </div>
    </div>

    <form class="row align-items-center" @submit.prevent="addSubject">
      <div class="col-3">
        <input type="text" class="form-control" placeholder="请输入科目" v-model.trim="subject" />
      </div>

      <div class="col-3">
        <input type="text" class="form-control" placeholder="请输入分数" v-model.number="score" />
      </div>

      <div class="col-3">
        <button type="submit" class="btn btn-primary">添加</button>
      </div>
    </form>
  </div>
</template>

<script>
export default {
  name: "App",
  data() {
    return {
      list: [
        {
          id: 100,
          subject: "语文",
          score: 99,
          time: new Date("2010-08-12"),
        },
        {
          id: 101,
          subject: "数学",
          score: 34,
          time: new Date("2020-09-01"),
        },
        {
          id: 102,
          subject: "英语",
          score: 25,
          time: new Date("2018-11-22"),
        },
        {
          id: 103,
          subject: "体育",
          score: 100,
          time: new Date("2020-12-12"),
        },
      ],
      subject: "",
      score: 0,
    };
  },
  methods: {
    del(index) {
      // 根据index删除list里的数据
      this.list.splice(index, 1);
    },
    addSubject() {
      console.log('提交');
      // 获取数组最后一条数据
      const last = this.list[this.list.length - 1];
      // 给数组追加数据
      this.list.push({
        // id，判断是否有最后一条数据，如果有，id取最后一条数据的id + 1
        // 如果没有最后一条数据，取默认id：100
        id: last ? last.id + 1 : 100, 
        subject: this.subject,
        score: this.score,
        time: new Date(), // 当前时间
      })
    },
  }
};
</script>

<style scoped>
.not-passed {
  color: red;
}
</style>
